English

Low-energy M1 states in deformed nuclei: spin-scissors or spin-flip?

Nuclear Theory 2023-04-24 v2

Abstract

The low-energy M1M1 states in deformed 164^{164}Dy and spherical 58^{58}Ni are explored in the framework of fully self-consistent Quasiparticle Random-Phase Approximation (QRPA) with various Skyrme forces. The main attention is paid to orbital and spin M1M1 excitations. The obtained results are compared with the prediction of the low-energy {\it spin-scissors} M1M1 resonance suggested within Wigner Function Moments (WFM) approach. A possible relation of this resonance to low-energy spin-flip excitations is analyzed. In connection with recent WFM studies, we consider evolution of the low-energy spin-flip states in 164^{164}Dy with deformation (from the equilibrium value to the spherical limit). The effect of tensor forces is briefly discussed. It is shown that two groups of 1+1^+ states observed at 2.4-4 MeV in 164^{164}Dy are rather explained by fragmentation of the orbital M1M1 strength than by the occurrence of the collective spin-scissors resonance. In general, our calculations do not confirm the existence of this resonance.

Keywords

Cite

@article{arxiv.2210.04701,
  title  = {Low-energy M1 states in deformed nuclei: spin-scissors or spin-flip?},
  author = {V. O. Nesterenko and P. I. Vishnevskiy and A. Repko and J. Kvasil},
  journal= {arXiv preprint arXiv:2210.04701},
  year   = {2023}
}

Comments

7 pages, 7 figures, submitted to Physics of Atomic Nuclei. arXiv admin note: text overlap with arXiv:2102.13580. As compared with the previous version, Ref. [1] was removed, Ref [33] was replaced, description of Fig. 3 was modified